forgot to mention that though the ABS system physically appears to be intact (senor wires, abs-ecu in the rear) while driving the light comes on and stays on, and having slammed on the brakes a few times in the 2 years ive had this particular car, at 50+MPH, the front and usually one of the two rear wheels lock. It was kinda scary..
----- Original Message ----- From: "Steven Hauptmann" <[email protected]> To: "'Adam Frank'" <[email protected]>; "A2-16v list (E-mail)" <[email protected]> Sent: Tuesday, October 19, 2004 1:53 PM Subject: RE: [a2-16v-list] New 2.0T 16V > The ABS is not activated during normal braking. So your problem may not be > the ABS. Pulsing can be caused by other things as well, like warped/heat > glazed rotors, sticking guide pins etc. Also, corrosion and internal muck > build up from infrequent brake fluid changes can cause pistons and valves to > stick. My rule is don't overlook the obvious. > > Of course your system could be getting erroneous signals.... VW added the > self-diagnosis and fault memory in '89 or '90 (check the Bentley for the > starting VIN). If you have this feature, a VAG-COM or the VAG1551 would save > you some aggravation. Don't know if you can blink out ABS codes or not. > > If not, Bentley covers in detail some simple functional tests for every ABS > system component except the control unit. All you need is the Bentley, an > Ohm meter and some coffee or beer, depending on what time in the morning you > get started. =) Shouldn't take long to bust it out > Don't forget to check the toothed rotors, which rotates through the wheel > speed sensors' magnetic field which generates the signal to the control > unit. I have heard of these getting damaged. > > We have ABS on the wife's 1991 200 20V and have yet to have any problems. On > that car, the ABS is absolutely transparent unless a wheel begins to lock > while braking....only then will the brakes pulse as the system reduces > hydraulic pressure from the affected wheel. > > > Steve Hauptmann > South Carolina > > -----Original Message----- > From: Adam Frank [mailto:[email protected]] > Sent: Tuesday, October 19, 2004 7:07 PM > To: [email protected] > Subject: Re: [a2-16v-list] New 2.0T 16V > > " I remember when people were up in arms about ABS. They were so worried > about > a computer thinking for them. Well, think about how much safer we are in > typical panic stops in the rain etc, than without ABS. Now we even have > brake assist, traction control, stability control.....margins for safety. " > > The ABS on my GLI has been flogged with problems for years. > > once driving the car long enough to warm up the brakes, the ABS light comes > on and stays on till i shut the car off. Any time i step on the brakes > firmly after that light is on, the brakes 'pulse' as i slow down instead of > allowing a smooth decline in speed.. Now i know this is partially ABS's job > to do so. But not all the time everywhere i go. Same problem happened on my > mom's '00 Hyundai; brakes pulse when she slows down. My GLi shows first hand > what a computer thinking for me can do, malfunction.... Maybe im too old > fashioned. > > By the way, anyone know of this problem? The ABS system seems to have a > 'brain' mounted in the trunk on the side. anyone else have their ABS light > come on for no reason? Ive checked myself and had the sensors checked. They > seem to be in place and nothing is out of the ordinary.. > > _______________________________________________ > a2-16v-list mailing list > [email protected] > http://mail.a2-16v.com/mailman/listinfo/a2-16v-list > For list archives, see listinfo link above.
